[GROOVY-6898] Changes to metaclasses should not leak into subsequent script executions

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.3.2
• Fix Version/s: 4.x
• Assignee: Unassigned
• Reporter: Jochen Kemnade
• Created: 27/Jun/14 03:41
• Updated: 27/Jan/20 10:54

Description

This is roughly related to GROOVY-5786.
When executing a script in the Groovy ScriptEngine (the JSR223 one) and that script makes changes to the metaclass registry, the modification will be available to the next script.
For example, If I execute

String.metaClass {
  foobar ={ 
    delegate
  }
}
print("Hello".foobar())

the script prints "Hello".
If I execute

print("Hello".foobar())

in the same engine again, it prints "Hello" again. I think it should throw a MissingMethodException.